Had a panic attack in the middle of work today

Haven't had one in a few months so I thought I was past this. Got hit with it out of nowhere during a meeting. My heart was racing, felt like I couldn't breathe, thought I was dying. Went to the bathroom and just sat there for like 20 minutes trying to calm down. Told my boss I wasn't feeling well and left. Now I'm worried about going back. This stuff sucks.